"She's excited," her rep tells the site. Due in September, this will be Robison's first child with boyfriend Martin Strayer. She has three children with her ex-husband, Charlie Robison: 9-year-old son Charles Augustus and 7-year-old twins Juliana Tex and Henry Benjamin.

Robison, 39, also plays with her sister, Dixie Chicks member Martie Maguire, in the country music and folk duo Court Yard Hounds. Strayer played acoustic guitar on the Court Yard Hounds' 2010 debut album. The Dixie Chicks last performed together last year and released their last studio album in 2006.